What is Presbyopia?
What is Presbyopia?
Presbyopia, Greek for "old eye," is when the eye has trouble focusing on near objects. It is a natural part of aging and typically starts after age 40.
As we age, the eye's clear lens, which helps the eye focus, becomes less flexible and more rigid. This makes it harder to focus light onto the retina (the light-sensitive tissue at the back of the eye), leaving close up vision blurry and unfocused.
Presbyopia is a type of refractive error (hard to see clearly) that affects about 150 million Americans. Luckily, presbyopia is easily corrected.2
Presbyopia is often confused with farsightedness (hyperopia), but the two conditions are different. Presbyopia results from a hardening lens, while farsightedness occurs because the eye shape is too short, allowing light to focus behind the retina instead of on it.
Symptoms of Presbyopia
Symptoms of presbyopia typically start after age 40 and gradually worsen until around the age of 65. Common symptoms include:4
- Difficulty focusing on close objects
- Eye strain when reading
- Blurry vision when reading small print
- Need for more light
- Headaches when working on near objects
- Need to hold reading material at arm's length
What Causes Presbyopia?
Presbyopia is caused when the eye's lenses gradually change shape and lose flexibility, reducing its ability to focus light. The leading cause of presbyopia is the natural aging process.
Risk Factors of Premature Presbyopia
People can get presbyopia before age 40. This is usually due to risk factors stemming from chronic medical conditions, eye trauma, and medications. This is called premature presbyopia, and risk factors include:
- Smoking cigarettes daily for over a year
- Poor nutrition
- Extended sun exposure
- Frequent alcohol consumption
- Multiple sclerosis
- Eye injury or disease
When to See an Eye Doctor
Visit an eye doctor when vision changes disrupt your quality of life and interfere with your ability to read and engage in near-vision tasks.
Noticeable vision changes might include:
- Blurred vision
- Frequent headaches
- Inability to focus on close-up objects
Seek immediate medical attention if you experience sudden vision loss in one or both eyes or have severe eye pain.
How is Presbyopia Diagnosed?
Presbyopia is diagnosed during a comprehensive, dilated eye exam administered by a licensed ophthalmologist. Because presbyopia is age-related, the American Academy of Ophthalmology (AAO) recommends people over 40 start getting routine eye exams.
Vision tests that are typically performed include:
- Refraction (tests distance and close-up vision)
- Near and distant visual acuity tests (how clear you see)
- Visual field test (looks at your side or peripheral vision)
- Eye muscle function test
- Tonometry exam (measures eye pressure)
- Pupil response test (how well your eyes respond to light)
Treatment Options for Presbyopia
Glasses, contact lenses, or eye surgery can easily correct presbyopia.
Reading glasses correct presbyopia for people who do not have other refractive errors (nearsightedness, astigmatism). Eyeglasses correct vision by bending light before entering your eye.
People can purchase eyeglasses over-the-counter (OTC) for mild presbyopia cases. Or, an eye doctor might prescribe reading glasses if more substantial vision correction is needed.
Bifocal lenses are eyeglasses that correct both near and distance vision. They are common among people who require a prescription for multiple refractive errors.
They have a visible line towards the bottom that separates the lenses. The top portion corrects far vision, and the bottom corrects near vision.
Trifocals are similar to bifocals, except three lens areas correct distance vision, mid-range vision, and near vision.
Multifocal lenses should not be worn while driving.
Like trifocals and bifocals, progressive lenses correct near, mid-range, and distance vision.
However, there is not a visible line that separates each lens. Instead, they are designed to gradually increase magnification from top to bottom.
2. Contact Lenses
Contact lenses are a good option for people who don't always want to wear glasses. They are thin, clear disks that sit on top of your cornea (transparent protective outer layer), correcting refractive errors.
There are two types of contact lenses that correct presbyopia: multifocal contacts and monovision contacts.
Multifocal contacts are designed to allow you to use both near and far vision simultaneously.
The contact lens disc is layered with different zones set to different powers, allowing the brain to select which power it needs to use to see clearly. It takes time to adjust to multifocal lenses, and objects can appear less sharp than with eyeglasses or other contacts.
Monovision contact lenses take a different approach to correcting presbyopia,. One lens corrects near vision, and the other corrects distant vision. Eye doctors also call this blended vision.
Because people typically have one eye that focuses better than the other, monovision is designed for the dominant eye to be corrected for distance vision. This leaves the other eye to focus on near objects.
Monovision has proven effective, but it takes time for your brain to get used to it, and some people have a hard time adapting.
3. Eye Surgeries
Monovision and refractive error correction are also achieved through eye surgery. Many people decide surgery is an excellent alternative to wearing glasses and/or contact lenses.
Laser-assisted in situ keratomileusis (LASIK) eye surgery corrects refractive errors using a laser to change the cornea's (transparent protective outer layer) shape. It does this by cutting into the outer layer of the eyeball. This allows light to bend and reach the retina (the light-sensitive layer at the back of the eye).
LASIK is highly effective at correcting vision. However, it isn’t for everyone, including people with the following risk factors:
- Continuously changing eye prescription
- Extreme nearsightedness, farsightedness, or astigmatism
- Thin cornea
- Uncontrolled diabetes
- Keratoconus (cone-shaped cornea)
- Severe dry eyes
Photorefractive keratectomy (PRK) surgery is similar to LASIK because it uses a laser to change the shape of the cornea.
However, PRK does not cut a flap in the cornea as with LASIK, making it a good option for people with thin corneas or dry eyes. It is also recommended for people with an active lifestyle or job.
PRK is also used to correct vision in people who have had cataract surgery.
Laser epithelial keratomileusis (LASEK) is laser eye surgery that only creates a flap in the cornea's delicate outer layer (epithelium) to correct refractive errors. This includes presbyopia.
Healing time takes longer with LASEK than with LASIK. However, people report slightly better long-term results. LASEK is a good alternative for people who do not qualify for LASIK.
Conductive keratoplasty (CK), also called NearVision CK, uses radio waves to change cornea shape to correct presbyopia and other refractive errors. This handheld procedure does not require cutting or tissue removal.
CK is an excellent option for people who are not candidates for laser eye surgery and/or who need to fine-tune vision after cataract surgery.
Intraocular lens (IOL) implants are artificial lenses used to correct refractive errors and replace natural lenses during cataract surgery.
There are several types of IOLs that depend on prescription and severity of the refractive error, including:
- Multifocal (multiple zones of lens power)
- Bifocal (two zones of lens power: near and far)
- Trifocal (provides a third focus)
- Refractive (multiple focal points allowing vision in all distances)
- Monovision (one eye corrects for near vision and the other eye corrects for far vision)
A corneal inlay is a small device implanted into the cornea using laser surgery. The device increases the depth of focus to correct close-up vision.
Corneal inlays are an excellent option for people who don't want to rely on reading glasses for reading. However, the procedure does not correct refractive errors (nearsightedness, farsightedness, astigmatism), so people with those eye conditions would not be good candidates for corneal inlay surgery.
Presbyopia Complications & Outlook
Presbyopia is a normal part of aging and will affect everyone. If left untreated, presbyopia will gradually worsen and significantly affect the quality of life. It will result in uncomfortable symptoms, including:
- Difficulty reading
- Trouble driving, especially at night
- Frequent headaches
- Difficulty working at a computer
- Trouble completing tasks that require close-up vision and focus
Fortunately, eyeglasses, contact lenses, or surgery can easily treat and correct presbyopia. While developing presbyopia can't be prevented, there are ways to reduce symptoms and maintain good eye health, including:
- Get an annual comprehensive eye exam
- Maintain a healthy diet
- Stop smoking
- Wear sunglasses when outside in the sun
- Control blood pressure and blood sugar
- Use good light when reading
- Limit time in front of a computer and smartphone
- Wear contact lenses and eyeglasses
Presbyopia is when the cornea becomes rigid and its elasticity gradually changes over time. This results in a loss of near vision and the ability to focus on close-up objects. It is part of the aging process and typically starts after 40.
Presbyopia symptoms include blurred vision, difficulty reading small print, frequent headaches, and eye strain.
Reading glasses, contact lenses, or surgery can easily treat presbyopia. If left untreated, it will gradually worsen, affecting the quality of life and the ability to do everyday activities.
In this article